Please please please read the literature on this issue. Eric Voth, M.D. is the most respected expert in the field.
http://www.medicalmarijuanaprocon.org/BiosInd/Voth.htm
Really? Here's his bio, from your link:
Dr. Voth "is recognized as an international authority on drug use and lectures nationally on drug policy issues. He has advised the Reagan, Bush and Clinton administrations and has advised or testified for numerous Congressional offices on drug-related issues. He was recently recognized by the former Director of the Office of National Drug Control Policy General Barry McCaffrey with the 'Director’s Award' for his outstanding achievement on combating drug use in our nation."
Most respected, all right...by the WODies. If it were up to me, I'd revoke his M.D. and make sure he never comes within a mile of a sick patient. He bases his opposition to medical marijuana on its being a "Schedule 1 drug" (whatever the f*** that means) instead of his opinion of its medicinal properties, defers to the incompetent FDA, and won an award from Barry McCaffrey. In what parallel universe can this guy pass as impartial?